Prenatal exposure to a ubiquitous household chemical increases risk for childhood eczema, according to a study by the Columbia Centre for Children's Environmental Health in New York City. Butylbenzyl phthalate (BBzP), used in vinyl flooring, artificial leather and other materials, can be slowly released into air in homes. Hereditary factors, allergens and exposure to tobacco smoke contribute to the condition. The study, which involved 407 non-smoking African-American and Dominican women and their children, found that onset of eczema by the age of two was 52 per cent more likely in children whose mothers had been exposed to higher concentrations of BBzP. The study was published online in the journal Environmental Health Perspectives.

Exercise versus cancer

It's known that exercise can reduce breast cancer risk, but University of North Carolina researchers have found that even mild physical activity can provide benefits. A study involved more than 3,000 women aged 20 to 98 years old, half with breast cancer and half without. The women were part of the Long Island Breast Cancer Study Project, looking for possible environmental causes of breast cancer. Women who exercised 10 to 19 hours per week during their reproductive or postmenopausal years had about 30 per cent reduced risk of breast cancer. Reductions were observed at all levels of intensity. 'A reduced risk of breast cancer for women who engaged in exercise after menopause is encouraging given the late age of onset for breast cancer,' says lead researcher Lauren McCullough.

Obesity and reward

The common contemporary view is that obesity is linked with the increased drive of the reward circuitry in the brain. But researchers at the Yale School of Medicine have turned this idea on its head: using transgenic mice in which hunger-promoting neurons had been altered or eliminated, the scientists showed that the reward aspect can be very high but subjects can still be very lean. In addition, some people who have no interest in food might be more prone to novelty-seeking behaviours and drugs such as cocaine. 'These hunger-promoting neurons are critically important during development to establish the set point of higher brain functions, and their impaired function may be the underlying cause for altered motivated and cognitive behaviours,' says study co-lead author Tamas Horvath. The study was published online in Nature Neuroscience.

Molecular gastronomy

University of Michigan scientists have found that a molecule called Sfrp5 could help fight obesity. Studying the signals that fat-storing cells send to one another, the study showed that Sfrp5 influences a signalling pathway known as Wnt to stimulate fat cells to grow larger and suppress the rate at which fat is burned in the mitochondria inside them. By stopping cells from making Sfrp5, mice didn't get fat as quickly because their fat cells didn't grow even when fed a high-fat diet. The study will be published in the Journal of Clinical Investigation. Researchers caution that the findings need to be explored further in both mice and humans.